This is just a heads up for IBC users using Paper Trading account. Interactive Brokers changed they default port number of paper trading accounts as per: https://www.interactivebrokers.com/en/index.php?f=15912
Default production port: 7496 (as before)
Default paper trading port: 7497
The assigned default API ports for production and paper accounts are now different to allow both accounts to run at the same time. Production port is still 7496 and paper port is now 7497. These ports are automatically assigned when TWS is installed or reinstalled. Likewise, IB Gateway users will see the change of default ports for paper go from 4001 to 4002, leaving 4001 for the production version.